1. Field of the Invention
This invention is related to welds between steel work pieces and, more particularly, to coatings applied to welds between steel work pieces.
2. Related Art
Gas-metal arc welding (GMAW), which is also known as metal inert gas (MIG) welding, is commonly employed to weld steel work pieces together in the automotive industry. A common problem with employing GMAW to join steel work pieces is the development of silicate islands of manganese, silicone, iron, oxygen and other trace alloys. Such silicate islands may inhibit the application of a coating onto the outer surface of the weld seam. For example, coatings applied through painting, phosphating and electrocoating (e-coating) may not adhere strongly to weld seams with silicate islands.
One approach to bonding painted, phosphated and electrocoated coatings with weld seams is to use a material abrasion process on the weld seam to remove the silicate islands. Another approach is to remove the silicate islands is through chemical processes. However, chemical processes may also be costly and may not result in sufficient removal of the silicate islands from the weld seam.
There remains a significant and continuing need for an improved process to join steel work pieces while allowing for painting, phosphating and electrocoating across the joint.